1 files changed, 19 insertions, 85 deletions

diff --git a/arch/x86_64/kernel/genapic.c b/arch/x86_64/kernel/genapic.c
index 0b3603adf56d..47496a40e84f 100644
--- a/arch/x86_64/kernel/genapic.c
+++ b/arch/x86_64/kernel/genapic.c
@@ -11,120 +11,54 @@
 #include <linux/threads.h>
 #include <linux/cpumask.h>
 #include <linux/string.h>
+#include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/ctype.h>
 #include <linux/init.h>
-#include <linux/module.h>
 
 #include <asm/smp.h>
 #include <asm/ipi.h>
+#include <asm/genapic.h>
 
-#if defined(CONFIG_ACPI)
+#ifdef CONFIG_ACPI
 #include <acpi/acpi_bus.h>
 #endif
 
 /* which logical CPU number maps to which CPU (physical APIC ID) */
-u8 x86_cpu_to_apicid[NR_CPUS] __read_mostly = { [0 ... NR_CPUS-1] = BAD_APICID };
+u8 x86_cpu_to_apicid[NR_CPUS] __read_mostly
+					= { [0 ... NR_CPUS-1] = BAD_APICID };
 EXPORT_SYMBOL(x86_cpu_to_apicid);
-u8 x86_cpu_to_log_apicid[NR_CPUS] = { [0 ... NR_CPUS-1] = BAD_APICID };
 
-extern struct genapic apic_cluster;
-extern struct genapic apic_flat;
-extern struct genapic apic_physflat;
+u8 x86_cpu_to_log_apicid[NR_CPUS]	= { [0 ... NR_CPUS-1] = BAD_APICID };
 
-struct genapic *genapic = &apic_flat;
-struct genapic *genapic_force;
+struct genapic __read_mostly *genapic = &apic_flat;
 
 /*
  * Check the APIC IDs in bios_cpu_apicid and choose the APIC mode.
  */
-void __init clustered_apic_check(void)
+void __init setup_apic_routing(void)
 {
-	long i;
-	u8 clusters, max_cluster;
-	u8 id;
-	u8 cluster_cnt[NUM_APIC_CLUSTERS];
-	int max_apic = 0;
-
-	/* genapic selection can be forced because of certain quirks.
-	 */
-	if (genapic_force) {
-		genapic = genapic_force;
-		goto print;
-	}
-
-#if defined(CONFIG_ACPI)
+#ifdef CONFIG_ACPI
 	/*
-	 * Some x86_64 machines use physical APIC mode regardless of how many
-	 * procs/clusters are present (x86_64 ES7000 is an example).
+	 * Quirk: some x86_64 machines can only use physical APIC mode
+	 * regardless of how many processors are present (x86_64 ES7000
+	 * is an example).
 	 */
-	if (acpi_gbl_FADT.header.revision > FADT2_REVISION_ID)
-		if (acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL) {
-			genapic = &apic_cluster;
-			goto print;
-		}
-#endif
-
-	memset(cluster_cnt, 0, sizeof(cluster_cnt));
-	for (i = 0; i < NR_CPUS; i++) {
-		id = bios_cpu_apicid[i];
-		if (id == BAD_APICID)
-			continue;
-		if (id > max_apic)
-			max_apic = id;
-		cluster_cnt[APIC_CLUSTERID(id)]++;
-	}
-
-	/* Don't use clustered mode on AMD platforms. */
- 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
+	if (acpi_gbl_FADT.header.revision > FADT2_REVISION_ID &&
+			(acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL))
 		genapic = &apic_physflat;
-#ifndef CONFIG_HOTPLUG_CPU
-		/* In the CPU hotplug case we cannot use broadcast mode
-		   because that opens a race when a CPU is removed.
-		   Stay at physflat mode in this case.
-		   It is bad to do this unconditionally though. Once
-		   we have ACPI platform support for CPU hotplug
-		   we should detect hotplug capablity from ACPI tables and
-		   only do this when really needed. -AK */
-		if (max_apic <= 8)
-			genapic = &apic_flat;
+	else
 #endif
- 		goto print;
- 	}
 
-	clusters = 0;
-	max_cluster = 0;
-
-	for (i = 0; i < NUM_APIC_CLUSTERS; i++) {
-		if (cluster_cnt[i] > 0) {
-			++clusters;
-			if (cluster_cnt[i] > max_cluster)
-				max_cluster = cluster_cnt[i];
-		}
-	}
-
-	/*
-	 * If we have clusters <= 1 and CPUs <= 8 in cluster 0, then flat mode,
-	 * else if max_cluster <= 4 and cluster_cnt[15] == 0, clustered logical
-	 * else physical mode.
-	 * (We don't use lowest priority delivery + HW APIC IRQ steering, so
-	 * can ignore the clustered logical case and go straight to physical.)
-	 */
-	if (clusters <= 1 && max_cluster <= 8 && cluster_cnt[0] == max_cluster) {
-#ifdef CONFIG_HOTPLUG_CPU
-		/* Don't use APIC shortcuts in CPU hotplug to avoid races */
-		genapic = &apic_physflat;
-#else
+	if (cpus_weight(cpu_possible_map) <= 8)
 		genapic = &apic_flat;
-#endif
-	} else
-		genapic = &apic_cluster;
+	else
+		genapic = &apic_physflat;
 
-print:
 	printk(KERN_INFO "Setting APIC routing to %s\n", genapic->name);
 }
 
-/* Same for both flat and clustered. */
+/* Same for both flat and physical. */
 
 void send_IPI_self(int vector)
 {